Circuit boards generally need a highly complex, highly precise, and high-density wiring layout. Thus, a conductive circuit of the circuit board needs to have small line width and small line spacing. Conductive circuit of the circuit board is made by: providing a copper clad laminate includes a copper foil, the copper foil includes a first patterned area and a second patterned area; plating copper circuit layer on the first patterned area, the second patterned area exposes through a clearance of the copper circuit; and etching the copper foil of the patterned second area. During the etching process, the copper circuit layer will be etched too. The bottom copper foil can be etched more than the upper copper foil, leading to undercutting, thus, reducing the binding strength between the substrate and the copper circuit layer. Improvement in the art is preferred.